6 steps to realize MCPCB manufacturing process
MCPCB stands for Metal Core Printed Circuit Board, representing an innovative circuit board design that utilizes metal materials as its substrate, delivering exceptional performance and reliability for electronic applications. In this article, we will delve into the manufacturing process of MCPCB to assist you in better integrating them into your projects.
Step 1: Structure of MCPCB
Before embarking on the manufacturing journey, it proves advantageous for your project to grasp the fundamental anatomy of the MCPCB board, a symphony of integral components, each harmonizing to orchestrate performance and functionality:
Shielding Veil: Crowned atop the MCPCB, the solder mask assumes a guardian's mantle, shielding the circuitry and components from the capricious external realm. Its duty extends beyond safeguarding against oxidation and corrosion, encompassing defense against the erosive touch of humidity and chemicals. Crafted from materials resistant to soaring temperatures, the solder mask stands resolute during the soldering ritual.
Conductor's Path: The circuit layer emerges as the heartstrings, weaving a tapestry of interconnected paths, uniting disparate components in symphonic resonance. Paved with conductive materials, these paths serve as conduits for the melodious transmission of electrical signals. The very design and arrangement of this layer dictates the circuit's virtuosity, a delicate dance of performance and stability.
Copper Symphony: The copper layer assumes a lead role within the circuit ensemble, its resonant notes plated upon the substrate canvas. A conductor of both electricity and thermal dispersion, copper conducts with prowess, orchestrating the flow of energy and maintaining harmonious temperatures across the board.
Insulating Barrier: The dielectric layer emerges as an intermediary guardian, positioned between the copper layer and substrate stage. This sentinel of insulation and support exudes its protective embrace. Often adorned with materials like prepreg (PP) or glass fiber (FR-4), its insulating aura harmonizes with mechanical fortitude, reinforcing the circuit's structural integrity and equilibrium.
Substrate Foundation: Anchoring the composition, the material substrate stands as the bedrock, an elemental foundation often embodied in aluminum alloy 5052. This alloy, endowed with virtuoso thermal conductivity and mechanical vigor, orchestrates the symphony of heat dispersion, seamlessly ferrying thermal energies from circuitry to the ambient realm, ensuring the circuit board's serenade remains steadfast and composed.
Step 2: Drilling Process of Metal Core PCB
The metal core's foundation is sturdier, ready for the precision dance of CNC drilling, enabling connections between layers and the installation of components.
Following the circuit design's blueprint, holes are strategically carved—process holes, fixing holes, via holes—each playing its designated role. Essential positioning holes are also etched, foreseeing the stages to come. Guided by a computer's commands, a drilling machine takes the lead. The operator sets the program, directing the choreography. Swift drilling ensures pristine hole walls, a robust base for reliable plating.
Drilling proceeds deliberately, as each hole is crafted individually. Progress is deliberate, but it ensures precision. Holes as small as 8 mils in diameter are achievable, a testament to the drill's finesse. Changing bits is a seamless transition; the machine selects the right bit, loading it onto the drill with automation.
Step 3: Make Outer Circuit Traces
An optically reactive organic film is applied atop the board's surface, capturing the design of the outer film through exposure. Following this, a secondary electroplating process is employed to enhance the thickness of the outer circuit.
Step 4: Apply Solder Mask
A liquid photosensitive varnish known as solder mask is carefully applied to both sides of the MCPCB. This layer serves as a safeguard, shielding the copper components from potential environmental factors like oxidation, dust, and other impurities that could lead to circuit disruptions over time.
Utilizing a CNC mill, the metal core circuit board's desired design outline is meticulously crafted. This technique, known as milling, involves the use of milling tools on a CNC machine. Milling is employed to shape the PCB's final outline during the PCB manufacturing process. Computer-controlled milling machines are harnessed for this purpose. Initially, the machine adeptly carves out any minor slots or internal cutouts. Following the path specified in the original tool file, the milling head traverses around each PCB. Equipped with brushes, the milling head ensures efficient dust collection by the vacuum system.
Step 6: V-Cut the Whole Panel
Incisions are etched onto the board's surface, simplifying the process of dividing the board. Referred to as V-cut, also known as V-Scoring or V-grooving, this marks the concluding phase in MCPCB fabrication. The technique involves crafting "V" shaped furrows on both the upper and lower sides of the PCB, leaving a minimal amount of material intact. This allows for effortless separation of individual PCBs from the production panel.
